Perturbative QCD, a universal QCD scale, long-range spin-orbit potential, and the properties of heavy quarkonia.

Abstract

A modified version of Richardson's potential is used to calculate the energies, fine-structure splittings, leptonic widths, and dipole transition rates of charmonium and the $\ensuremath{\Upsilon}$ system. The effects of the perturbative color-magnetic (spin-dependent) potentials are included to the full radiative one-loop level. The question of the consistency of the data with a universal QCD scale and its expression in the central and spin-dependent potentials is addressed.